Industrial dry cleaning cooker-still

ABSTRACT

An industrial dry cleaning cooker-still for salvaging solvent such as perchlorethylene from oil residues comprises a cylindrical tub mounted horizontally and provided with heating ducts on the outside wall of the lower half portion thereof and with a surrounding jacket to form an air chamber open at the bottom and top for causing the upper half portion of the tub to be heated by convection. A rotor in the tub has a series of blades successively spaced along and around the rotor shaft which are set oblique to provide a screw propeller effect on the contents. The blades have outer arcuate edges adjacent to the wall of the tub and have leading and trailing cutter fins. The rotor is driven back and forth in opposite directions so that it will churn and cut up the contents while shifting the same back and forth along the tub. A scouring powder is added to the oil residue to keep the walls of the tub clean of encrustation. Upon driving the rotor in one direction only the contents are propelled out an unloading door.

INDUSTRIAL DRY CLEANING COOKER-STILL 4 Sheets-Sheet 1 Filed Feb.

INVENTOR ALBANIS P. MCCANDLISH AGENT June 27 1972 l A. P. MCCANDLISH3,612,958

INDUSTRIAL DRY CLEANING COOKER-STILL Filed Feb. 9, 1970 4 Sheets-Sheet 2CONDE/USER Bax INVENTOR ALBANIS P. MCCANDLISH AGENT AME /A/LET as STE/7MDUC 7" 4 Sheets-Sheet 5 A. P. MGCANDLISH INDUSTRIAL DRY CLEANINGcooKER-STILL June 27, 1972 Filed Feb.

Al M E E a, Wp 3 l A/ el. VP L n 6 d H||IE M \m= mf uw 4 e 6 5 T01 4 m 22 IAT 4 7 w.: E@ 2 4 L 8T@ 2 m f D Ilm ww .E S nn uw Mm m mw ff 2; F9 r4 5 s 2 2 |H|Iu n A G m W 12E: 5 m m E. Mm g A 6 L ww, we 3 2 Ma J am 2O L mdf .Il "Il m l l l n l l l I l f- INVENTOR ALBAN|5 P- MCCANDLSH BY/LvL 7V- AGE T June 27, A. P- INDUSTRIAL DRY CLEANING COOKERSTILL 4Sheets-Sheet 4 Filed Feb. 9, 1970 INVENTOR ALBANIs P. MCCANDUSH AGENTUnited States Patent O 3,672,958 INDUSTRIAL DRY CLEANING COOKER-STILLAlbanis P. McCandlish, Cincinnati, Ohio, assigner to McGraw-Edison,Elgin, Ill. Filed Feb. 9, 1970, Ser. No. 9,698 Int. Cl. B01d 3/02, 3/00, 1 /00, 1/30; B011? 11/60;

Dof 29/00 U.s. cl. 2oz- 17o 2 Claims ABSTRACT OF THE DISCLOSURE Anindustrial dry cleaning cooker-still for salvaging solvent such asperchlorethylene from oil residues comprises a cylindrical tub mountedhorizontally and provided with heating ducts on the outside wall of thelower half portion thereof and with a surrounding jacket to form an airchamber open at the bottom and top for causing the upper half portion ofthe tub to be heated by convection. A rotor in the tub has a series ofblades successively spaced along and around the rotor shaft which areset oblique to provide a screw propeller effect on the contents. Theblades have outer arcuate edges adjacent to the wall of the tub and haveleading and trailing cutter fins. The rotor is driven back and forth inopposite directions so that it will churn and cut up the contents whileshifting the same back and forth along the tub. A scouring powder isadded to the oil residue to keep the walls of the tub clean ofencrustation. Upon driving the rotor in one direction only the contentsare propelled out an unloading door.

An object of the invention is to provide a novel form of suchcooker-still which has improved operating eiciency and an improvedaction which maintains the tub walls clean of encrustation to avoid theneed for any difficult manual cleaning operations.

Another object is to provide such cooker-still which when the motor isdriven in one direction only will propel the contents out through anunloading door at one end of the still.

These and other objects and features of the invention will be apparentfrom the following description and the appended claims.

In the description of my invention reference is had to the accompanyingdrawings of which:

FIG. l is a perspective view of the present cooker-still;

FIG. 2 is a rear View with parts broken away;

FIG. 3 is a vertical section taken on the line 3-3 of FIG. 2;

FIG. 4 is a fractional side View showing the heating ducts; and

FIG. 5 is a perspective view partly broken away of the rotor bladearrangement.

The present cooker-still comprises a cylindrical tub (FIGS. 2 and 3)welded at the ends to rectangular walls 11 and 12 (FIG. 3). The topcorner portions of the front and back end walls are joined at the sidesof the tub by inverted U-shaped angle iron structures 13 (FIG. l). Theseangle iron structures are joined at the ends of the tub by lateral angleirons 14 (FIGS. 2 and 3). The lower corner portions of the front andback end walls are joined at the sides of the tub by upstanding U-shapedangle iron structures 15. The latter structures 15 extend below the endplates to form a pair of legs by which the cooker-still is set on a Hooror other support. At the axis of the tub there are end bearings 16 and17 (FIG. 3) in which a rotor shaft 18 is journaled. The shaft has anoutward eX- tension at one end provided with a drive sprocket 19 coupledby a chain 20 to a drive sprocket-21 (FIG. 2) of a motor 22. The motoris supplied with power as from a "ice 110 volt A.C. line via a switchbox and reversing timer 22a (FIG. l) typically of the smallmotor-operated cam type. Typically, the motor will drive the rotor shaftat about 3 r.p.m. and the timer will reverse the motor about twice perminute. The reversing timer may however be cut out at will as bypressing a push button 22b so that then the motor will drive the rotorin one direction only for unloading the tub as is later described.

The rotor shaft 18 (FIGS. 2 and 3), which is square in cross sectionexcept for its journaled end portions, has a series of U brackets 23riveted thereto at equal intervals therealong with each being advancedby from the preceding one. Secured to these U brackets are radial arms24 the outer ends of which have oblique slots receiving respectiveblades 25. Each blade has an arcuate cutter edge 26 uniformly spacedfrom the inside wall of the tub. These blades are provided with cutterfins 27 and 28 (FIGS. 3 and 5) at the leading and trailing edges withthe cutter fins being positioned at right angles to the shaft 18. Theblades are all set oblique in the same direction so that when the shaftis turned in one direction only they will have a screw propeller effecton the contents to move the same along the tub while at the same timethe arms 24 have a churning effect and the fins 27 and 28 have a cuttingeffect to avoid conglomerating the contents into any one large masswhich might stall the drive motor. However, during the operation of thecooker-still the drive motor is reversed at regular intervals, asabove-mentioned, the effect of which is to shift the contents back andforth along the tub while churning and cutting up the same.

In the front end wall 11 there is an unloading door 29 (FIG. l') openingto the lower half portion of the tub. This door is held closed by twodiametrical extensions 30 having slots 31 extending up from the bottomand receiving screw clamps 32 to hold the door tightly closed against asealing ring, not shown. When the screw clamps are unthreaded slightlythe door can be lifted from its mounted position. When the door isopened and the drive motor is turned in an unloading direction only thecontents are propelled along the tub and out of the opening by thepropeller action of the blades.

The contents comprise principally a heavy oil resid-ue laden withperchlorethylene which must be heated as it is churned to drive off theperchlorethylene to be salvaged. 'Ihe oil residue is fed into one end ofthe tub via a pipe P, (FIGS. l and 3) and a lter powder or filter sludgecontaining such powder is fed into the other end of the tub via a pipeP2 (FIGS. 2 and 3). The filter powder serves to scour the inside wall ofthe tub` as the contents are churned back and forth by the rotor blades25.

The tub is heated by steam ducts 33 (FIGS. 3 and 4) applied back andforth in side-by-side arrangement length- Wise of the tub over theoutside wall of the lower half portion thereof. The ducts are in twogroups each applied over about one-fourth the circumference of the tub.Steam from a suitable source is fed Via ducts 34 and 35 (FIGS. 1 and 2)to the upper ends of the respective groups of heating ducts. The lowerends of the two groups off ducts are joined at the bottom by a pipe 36and provided with a common outlet 37 for the condensate.

Surrounding the tub and steam ducts in spaced relation thereto is ajacket 38 (IFIGS. l and 2) sealed at the ends to the two end walls 11and 12. This jacket has an air inlet opening 39 longitudinally of thetub at the bottom thereof and an air outlet opening 40 longitudinally ofthe tub at the top thereof. The air is thus drawn in from the bottom andexpelled at the top by the heating action of the steam ducts, and may beeven moved by forced circulation if desired, to cause the upper part ofthe tub to be heated from the steam ducts by convection.

As the oil residue contents are heated and churned back and forth theperchlorethylene vapors are driven off and fed by insulated pipes 41 and42 (FIGS. 1, 2 and 3) through the end walls 11 and 12 to a condenser box43 mounted on standards 44 at the top of the tub. These condensers areprovided with finned coils 45 (FIG. 3) through which cooling water ispassed via inlet pipes 46 and outlet pipes 47. The vapors enter thecondenser typically at 250 F. and are condensed by the cooling coils anddrained as a liquid at the bottom into a water separator 48 (FIG. l1).After being freed of water content by the separator the essentially pureperchlorethylene is drained off by a pipe 49 into a suitable storagetank not shown. Since in industrial dry cleaning there is a highproportion of oil in the dirty solvent, there is a heavy concentrationof oil with the filter powder after the mixture is cooled dow-n. The oiland powder settle to the bottom. The free oil is drawn olf through aspigot S ('FIG. 1) before the door 29 is opened to unload the oilsaturated powder.

From the foregoing description it will be apparent that novel featuresof the invention reside in a cylindrical tub horizontally mounted sothat it is adapted for automatic cleaning and unloading, in a uniqueagitator which is reversed periodically to mix, churn and shift thecontents back and forth while cutting up the contents into small massesfor efficient removal of the perchlorethylene, in heating the lower halfof the tub by steam ducts while providing a surrounding jacket for airow effective to heat the upper part of the tub by convection, inchurning and agitating the contents by oblique scraper blades whichcontinually scour the inside wall of the tub to keep the walls clean ofencrustations and in driving the rotor blades in one direction onlyduring unloading to move the contents out of one end of the tub by ascrew propeller action. These features have not only proven to give avery efficient distilling action but by tests and field operation theyare found to eliminate the necessity for hand scraping and chiseling ofbaked-on residue as has been required with commercial dry cleaningcookerstills of the prior art.

The embodiment of my invention herein particularly shown and `describedis intended to be illustrative and not necessarily `limitative of myinvention, since the same is subject to changes and modificationswithout departure from the scope of my invention, which I endeavor toexpress according to the following claims.

I claim:

1. An industrial cooker-still comprising a cylindrical tub for a contentof solvent, oil residue and scouring powder, means mounting said tub inan axially horizontal position, a rotor shaft in said t-ub journaled atthe axis thereof, narrow radial arms on said shaft having relativelywide blades mounted on the outer portions thereof, said blades havingouter arcuate edges adjacent to the 4 inside wall of said tub, saidblades being set oblique relative to the circumferential paths of travelthereof giving a screw propeller effect during rotation of the shaftwhile said radial arms have a churning effect on said contents, meansfor driving said rotor shaft alternately in opposite directions wherebyto agitate and concurrently shift said contents back and forth with ascrubbing action along the wall of the tub, and said blades being pro-'vided respectively at their leading and trailing side edges withleading and trailing cutter fins at right angles to said shaft forcutting the contents into small masses as the rotor shaft is turned ineither direction.

2. An industrial cooker-still comprising a cylindrical tub for a contentof solvent, oil residue and scouring powder, means mounting said tub inan axially horizontal position, a rotor shaft in said tub journaled atthe axis thereof, narrow radial arms on said shaft having relativelywide blades mounted on the outer portions thereof, said blades havingouter arcuate edges adjacent to the inside wall of said tub, said bladesbeing set oblique relative to the circumferential paths of travelthereof giving a screw propeller effect during rotation of the shaftwhile said radial arms have a churning effect'on said contents, meansfor driving said rotor shaft alternately in opposite directions wherebyto agitate and concurrently shift said contents back and forth -with ascrubbing action along the wall of said tub, and cutter fins on saidblades in line with the direction of travel of the blades to slice upthe oil residue with said scouring powder and prevent the same fromconglomerating into large masses which might stall the drive of therotor.

References Cited UNITED STATES PATENTS 3,169,537 2/ 1965 Fuhring 134-1112,318,455 5/ 1943 Black 202-170 1,935,183 11/1933 Hapgood 202-181 X2,123,439 7/1938 Savage 202-170 D 2,140,623 12/ 1938 Hetzer 68-182,427,718 9/1-947 Denys 203--89 X 2,779,723 1/1957 Prymek 202-1702,801,958 8/1957 Fortenbacher et al. 202-170 2,832,726 4/1958 Norment202-181 1,775,017 9/11930 Carleton 219'38 2,484,070 10/ 1949 Boyce259--45 2,563,937 8/1951 'Keight et al. 259-9 3,273,863' 9/ 1966 Lodigeet al 259-9 3,368,723 2/ 1968 Hardeman 259-39 NORMAN YUDKOFF, PrimaryExaminer I. SOFER, Assistant Examiner U.S. Cl. XB.

